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In this third and final post on the topic of Ethereum, Dr. Neeraj Oak sums up his thoughts on this potentially ground-breaking decentralised contracting system and considers the issues and benefits he thinks should be highlighted before Ethereum is launched.

To summarize my view in the previous two posts, Ethereum is a good idea but one that is far more complicated than even Bitcoin was at its inception. This is an admirable thing, but it is important to provide credible solutions to the rather fundamental legal and technical issues that Ethereum faces before it is officially launched. Without these, Ethereum seems a risky proposition for any investor.

One vital part of creating a sound market proposition for Ethereum is in crafting a cohesive argument for why their service is better than a centralised, non-pseudonymous alternative. If the argument centres on the idea of a safe means of transferring data or value, then eliminating pseudonimity is a good way of achieving this. On the other hand, if the goal is to eliminate the need to trust a single central authority then this could be achieved in easier ways. For instance, making several independent organisations responsible for maintaining copies of the ledger would preserve a part of the checks-and-balances of full decentralisation without exposing ordinary users to the hassle and potential threats that could come from holding a copy of the ledger themselves. Without explicit reasons for including the design features of pseudonimity and decentralisation, Ethereum risks looking like a purely ideologically motivated experiment rather than a practical alternative for mainstream users.

It is also worth considering the merits and drawbacks of making the Ethereum project fully open source during development. While this certainly increases the confidence and engagement of the cryptocurrency community, it also makes it hard to keep competitors and clone services out of the market. Ethereum will live or die by its ability to get third party developers to utilise its smart contracts and scripting language. If Ethereum’s code can be easily reproduced, then it faces a real risk of being outcompeted by a cloned or forked service with a better marketing department. In response to this issue, supporters of Ethereum have made the argument in the past that the best guarantee of a quality service is the participation of its creators. I’m afraid I don’t subscribe to that view; the very fact that Ethereum is being developed a mere 6 years after the launch of Bitcoin suggests that open source projects are very susceptible to competition from new innovators from outside the immediate circle of their creators. More to the point, the effort of fighting off forks and clones will be a distraction to the Ethereum team, win or lose.

I’ll finish with this thought: the reasons why Bitcoin is the dominant cryptocurrency today is not only that it was first. It is also because it launched at a time when hardly anyone had heard of the concepts it espoused, and fewer still believed in them. Through its early years, it was obscure and barely capitalised. I believe that it was this period of insignificance that gave the Bitcoin community the time to find answers to its early critics in a relatively technical, low-stakes environment. In contrast, Ethereum will be launched with its coffers filled and in the full glare of the media spotlight. Its creators should prepare for a rocky few months after its launch.

In the second post on the topic of Ethereum, Dr. Neeraj Oak examines some of the outstanding technical and legal challenges that Ethereum faces.

In this post I’m going to give a brief outline of the kinds of challenges and obstacles that Ethereum will have to overcome before it launches. But before I do that, I want to consider some of the advantages that Ethereum could bring to the virtual currency community.

Bitcoin was designed to be a value transfer mechanism, but in its original form it only supports the transfer of one commodity: Bitcoins. In recent years, the idea that other commodities could be traded on the Bitcoin blockchain has grown in popularity. So-called coloured coins have been proposed that can be used to represent other items on the blockchain, using the benefits of decentralisation to record ownership without the need for a trusted third-party registry.

If Ethereum achieves what it has set out to do, it would represent a far more flexible implementation of the coloured coin concept, not only allowing other commodities to be traded but also enabling the creation of complex trading instruments like derivatives and options. It would also open up the possibility of decentralised versions of existing services such as Dropbox.

If it succeeds, Ethereum holds a great deal of promise in terms of the opportunities it would open up for entrepreneurs in the blockchain technology space. But for this to happen, Ethereum must tackle a few serious concerns about its technical operation and the legal ramifications users may face by using Ethereum contracts.

Technical issues

Bitcoin’s creators are believed to have purposely left Turing-completeness out of their service because of the unnecessary hassles it creates. For instance, when code is executed in a pseudonymous decentralised system, the processor of that code is unaware of its origin. This is dangerous, since the code could be malicious, both in its operation on the funds it is given and its interaction with the computer on which it is being processed.

As an example, imagine an Ethereum user who decided to upload a virus to the blockchain. This virus would be contained within a smart contract and would eventually reach a processor for execution. If the processor attempts to execute the code without any safeguards, they could risk infecting their own computer. However, if they were to somehow screen the code before processing, they may have to perform considerably more computations (in verifying the code is secure) than they are being paid for. Further, even the most sophisticated screening process cannot guarantee that any piece of code is safe to execute, so processors would still run a risk of infection even after they take due precautions.

Ethereum partially addresses this problem by forcing a finite execution time on all contracts by charging the contract ether for the computational time it takes up. This makes infinite loops impossible, because they would require infinite money to perform. Unfortunately, this does not tackle the security challenge of finitely long malicious code.

Legal issues

An immediate problem with the idea of smart contracts is that in practice it is hard to hold anybody to account for their actions. Because the contracts execute autonomously from their creators once deployed, their activities are hard to stop should they become destructive or malicious. Moreover, one cannot track down the creators of the code easily because Ethereum upholds the principle of pseudonimity, the representation of users with account numbers or public keys. Even if the creator of a piece of malicious code were located, it would be difficult to punish him/ her for the potentially unintended or unforeseen actions of their autonomous code.

It may also be the case that a smart contract created between two people was the result of deception or coercion. Ordinarily, a physical contract drawn up by two parties is witnessed by independent signatories to minimize the risk of coercion. However, in the digital world there is no way of knowing if one of the parties signing the contract is doing so against their wishes. Moreover, neither party has any recourse to a court of law should the contract have been misrepresented, since it is unclear which nation’s jurisdiction applies. After all, the contract signatories may be in different countries, as may be the processor who executed the contract code. As a further complication, the execution of the contract cannot be stopped once it has been deployed, so in practice the only law that counts in the world of Ethereum is the computer code that resides within each contract. This leaves users of such contracts dangerously exposed, something that they should be made aware of before they put their digital signatures to any smart contract.

Ethereum is an innovative idea, but one of the problems with innovations is that they stretch the institutions that already exist in our societies. This would not be a problem if the idea was to remain experimental, but as things stand at least $15 million worth of investment has been put into Ethereum and several million more may follow once the service is brought to market. If credible solutions to the legal issues that Ethereum could face were not made public by then, the creators of Ethereum should probably prepare to face some stern criticism.

Join me for my next post, in which I sum my views on Ethereum and the possible risks and rewards it offers to investors.

A great deal of publicity has surrounded the development of Ethereum, the decentralised contracting platform. Over the next few posts, Dr. Neeraj Oak considers what Ethereum offers, and the benefits and obstacles it might face as it is brought to market.

I’ve had a lot of people asking me about Ethereum lately. It has been a hot topic among virtual currency enthusiasts, partly due to Ethereum already claiming to have raised around $15 million worth of Bitcoins from its initial sale of Ether, the value unit of the Ethereum system.

In this post, I’d like to cover the basics of what Ethereum claims to be and what differentiates it from existing virtual currencies such as Bitcoin. But before I begin, it’s worth stressing that Ethereum has not yet launched so we can’t know for sure if its final feature set will live up to the ambitions of its developers. Consequently, we can only base our knowledge of its features on the project yellowpaper and public code.

What is Ethereum?

Bitcoin, the first and largest of the cryptocurrencies, works on the principle of a decentralised blockchain in which transactions are registered. When a user requests a transaction, the system bundles it up with a set of other transactions into a mathematical puzzle called a block. This block is solved by transaction processors (or miners) who expend computational effort on the problem in return for a monetary reward. This system makes the history of Bitcoin transactions tamper-resistant, an important feature when dealing with people’s money.

Ethereum will also be a decentralised exchange system, but with one big distinction. While Bitcoin allows transactions, Ethereum aims to offer a system by which arbitrary messages can be passed to the blockchain. More to the point, these messages can contain code, written in a Turing-complete scripting language native to Ethereum. In simple terms, Ethereum claims to allow users to write entire programs and have the blockchain execute them on the creator’s behalf. Crucially, Turing-completeness means that in theory any program that could be made to run on a computer should run in Ethereum.

As a more concrete use-case, Ethereum could be utilised to create smart contracts, pieces of code that once deployed become autonomous agents in their own right, executing pre-programmed instructions. An example could be escrow services, which automatically release funds to a seller once a buyer verifies that they have received the agreed products.

Because the execution of code costs time and computational capacity, the people who process Ethereum contracts (analogous to Bitcoin’s miners) must be compensated. As such, Ethereum contracts are issued along with a finite amount of ether, the value token of Ethereum. When the code is processed, the processor receives a predefined amount of ether from the contract for the work they put in. By making code costly, the designers of Ethereum also hope to limit the size of their blockchain, since it could quickly balloon to a size that dwarfs Bitcoin’s if safeguards were not put in place. In the short term, it also creates an income for the creators of Ethereum: the money they have raised so far has come from the pre-sale of ether.

Ethereum contracts are designed to be ‘fuelled’ by ether, so the designers of the system have chosen to inject 18 million ether units into circulation through mining each year in perpetuity. This is unlike the Bitcoin model of mining, which has diminishing returns that result in a long term limit in the quantity of value tokens in circulation.

Join me for my next post, in which I look at some of the outstanding technical and legal challenges that Ethereum must overcome before it reaches the market.

In the context of the dramatic price changes faced by Bitcoin in recent weeks, Dr. Neeraj Oak explains why it isn’t all bad news for the supporters of virtual currencies.

With the price of Bitcoin continuing to fall from the dizzying peak of over $1100 in December 2013 to a current value of around $300, it is easy to assume that this is a very bad thing for the virtual currency community. In reality, it might actually be a blessing in disguise. Here are three reasons why:

Reason #1: High prices dissuade new users

The operating model of any virtual currency is to grow its user base to become as widely accepted as possible. However, if the price of the currency is too high, this can become a psychological barrier to new adopters, who may feel that they do not get a good deal when they exchange fiat money for Bitcoin. This is especially true when one considers that the price of Bitcoin in September 2014 was around 100 times greater than its price in January 2012. New users may find it unsatisfying to pay such a high price for a commodity that was so recently considerably cheaper.

A lower price for Bitcoin is helpful in this respect, but what is even more important is that the price becomes stable. This does not mean a stagnant price, but rather one that has a relatively predictable trend. Volatility and uncertainty are not attractive features for new adopters.

The price of Bitcoin towers above all the major alternative virtual currencies in the market today. A high price often brings the added advantage of greater visibility and prestige for the currency, making potential investors and adopters sit up and take notice. One of the problems of the dominance of Bitcoin is that many of the newer, smaller virtual currencies have struggled to find the limelight. With the price of Bitcoin falling, opportunities may appear for these currencies to garner more attention. Ultimately, this is beneficial for the virtual currency community; these alternative virtual currencies tend to be at the forefront of innovation in the field, and increasing their profile will help to spread ideas that could improve the prospects of all virtual currencies.

Reason #3: Deflation encourages speculation

Throughout the meteoric rise of Bitcoin stories have spread of the enormous fortunes made by early adopters. So long as the price of Bitcoin continued to increase, the idea that such price rises were somehow systemic became almost credible. When investors believe that the price of a commodity is bound to rise, they will often pay over the odds to acquire it, raising the price further. On the other hand, people using Bitcoin as a transaction method would be at a disadvantage, since the prices of goods and services that can be bought using Bitcoin often lag behind the headline Bitcoin price.

The result of sustained increases in Bitcoin prices is that it becomes a speculative vehicle rather than a transaction vehicle. This crowds out the true value makers in the currency: the consumers and merchants. Without these two groups of Bitcoin users, it is hard to conceive of a sustainable business model for Bitcoin- it would merely be a speculative bubble.

The recent fall in Bitcoin prices will do a lot to dispel the myth that short-term investments in Bitcoin are bound to pay off because it is a deflationary currency. With luck, this will help to drive away the types of speculators who drive the notorious volatility of Bitcoin prices.

To summarise, the recent fall in Bitcoin prices may have been painful for many of its users, but may help to create a healthier, more sustainable virtual currency. The Altcoin community too should take note; this could be their chance to assume the leadership position in the rapidly changing virtual currency domain.

As we continue to experience regular occurrences of Bitcoin volatility, I wonder if and when Bitcoin might become too big too fail. As it continues to go mainstream if its Achilles Heel of Volatility gets further exposed, and the worst happens, who will care? If we visualise the rescue meeting, who is likely to accept a seat at the table?

Bitcoin, together with Altcoins and alternative currencies continues to excite interest across multiple segments around the world. In spite of warnings from CFPB, FATF, EBA and other regulators, news of Bitcoin related conquests continue to come thick and fast.

One thing that experts seem to agree about is that this is not going away any time soon. But as the movement gathers momentum and becomes increasingly entwined with mainstream ecosystems, a lot more businesses and consumers could potentially stand to lose if the services were to fail.

Reportedly Bitcoin is making strides in Australia. Living Room of Satoshi reports that Australian residents have paid $150,000 toward BPAY-enabled utility bills, electricity bills, school fees and tax payments through their service. BPAY is an important bill-payment system in Australia and supports innovative ways to pay through digital banking, QR Codes and more.

Bitcoin bill payments is also happening in Canada, and elsewhere in the world too, Bitcoin is becoming a part of everyday life. Overstock plans to launch International Bitcoin Payments on September 1st. Yet, more bill payment and more retail payment may not necessarily translate to Happy Days. Retailers need fiat currency, and the more the mainstream services, the more the potential exposure to currency quirks.

As prices declined this week, and Bitcoin experienced one of the most volatile periods this year, reportedly going into a 38% free fall in some areas yesterday, I wonder whether the industry is already showing signs of age. Still in the first flush of growth, the industry must nevertheless go through all the growth phases of its predecessors, however different they may seem. But when teenage angst gives way to middle age worries, who will take care of Bitcoin?

Studying trends in Digital Money as we do, it seems as if each wave of new entrants and services seems indomitable at first, but may be brought down by some of the very factors that at first made it successful. Mobile money services can find it hard to support the very high volume low value transactions that are their reason for being. Money transfer operators feel the heavy burden of compliance due to the highly specialised nature of their business and their sprawling agent networks that made them successful for so long. And we all know what happens when banks become too big to fail: every one gets roped in to take care of them. But more importantly processes exist for detection and correction in these industries, and remedial action can proceed along well understood lines.

As the Cryptocurrency industry enters it’s sixth year, some of the processes have already been streamlined for efficiency. However this very maturity is exposing its Achilles heel of Volatility in new ways. The fact that it is possible to attack a pool more easily than the same number of independent miners, for instance, raises new possibilities for attacks as we saw recently. At the start of the month one hacker was revealed to have stolen $83,000 over four months by targeting a mining pool and using a vulnerability in the border gateway protocol.

A number of incidents, such as Mt. Gox have brought home the vulnerabilities of doing business involving Bitcoin. When traditional businesses fail, there are fall backs typically at the country or economic zone level. If the industry is to grow out of adolescence is it possible to put trusted guardians and a protection mechanism in place?

Cui Bono? Although it is clear that everyone stands to benefit from their being such a mechanism, it is not clear who stands to benefit from being such a mechanism.

Yet this will be vital for when cryptocentric systemically critical services such as Bitcoin need to be stabilised or bailed out. Otherwise the knock-on effect to other parts of the ecosystem will increasingly translate the shock onward, not just to Litecoin, Darkcoin and other cryptocurrencies as recently happened, but even to external entities that may seem totally disconnected at present.

Thanks for the outpouring of support to me, on the publishing of my first book, The Digital Money Game, now available on Amazon sites around the world. After I last shared about it, A number of you asked me what made me want to write this book, so I’d like to say a bit about this today.

When I strayed into the world of payments, after being in Telecoms for many years, it opened my eyes to so many new possibilities. This was around 2005 and it seemed to be a no-brainer for a telecoms operator to build new revenue streams from payments.

This proved elusive though. Firstly it was a personal challenge to try to understand so many new areas all at once, and then be able to position the business case to top management in a way that communicated both opportunities and risks. All of us had spent our lives in Telecoms, IT and non-Payments functions, and we had to rapidly understand Payments, E-Money, Regulations, Prepaid, Cash Networks and all this across multiple geographies.

Regulations did not help. At the time I blamed myself, thinking there was something more I could do. Ten years later, having worked with a world leading bank and the largest money transfer operator in the world, I got to understand regulations so much better. Now I KNOW there was little else I could do: One depends on regulators, who themselves have such a difficult time coping with the large number of changes, with a heavy burden of responsibility on their shoulders.

The truth is, this is all new. We are all learning. But that doesn’t take away the stress of not knowing, as so many of you across the world would agree! I wish I had had someone to tell me what was happening, how it would affect me and what I needed to know to stay ahead. I wanted practical cases I could learn from, and reassurance that this was an exciting space to build a new career.

This is my chance to make that wish a reality for others, by sharing the lessons I learnt and offering some tips from over 10 years I have spent launching services of the different kinds discussed in this book. I hope it will help you in some small way, to reinforce decisions you have to make, to help you to put your case forward to management and most of all to feel good about yourself and what you are achieving in this highly competitive and changing space.

I would love to hear your feedback. Did this book help you? What further questions did it raise?

Click here to go to the Amazon site. To your right you will see a green panel suggesting the most convenient online store for you. Do let me know if you face any difficulty getting access.

Dr. Neeraj Oak considers the size of Bitcoin and its scope for the future compared with other players and industries.

In this post, I will provide a context in which the size of Bitcoin, both present and future, can be judged. The true size of Bitcoin is often skewed in the media through qualitative descriptions; I will look at it quantitatively, and compare it with other relevant organisations and markets.

Let’s start with the cryptocurrency industry. I will show values as squares, with the area of the square proportional to its value.

Using market capitalisation as a proxy for size, we can see that Bitcoin forms very nearly the entirety of the cryptocurrency industry. Perhaps this isn’t surprising, given the earlier start and greater publicity Bitcoin enjoys over the other 670 alternative coins in more than 50 exchanges. Moreover, many of the other cryptocurrencies use Bitcoin as a basis of operation or an intermediary; thus the growth of these currencies will actually spur growth in Bitcoin.

Let’s take a wider view. I’ve been asked about how cryptocurrencies could affect energy markets, as more computing time and energy goes into mining coins. The intrinsic link between the electricity used to mine a coin and its value was originally used to set the price of the first Bitcoin. It seems fitting to start by considering how Bitcoin compares to the world energy industry.

According to one estimate, the world energy market is worth around $5 trillion a year. Comparing this to cryptocurrencies by their market capitalisation isn’t a perfect analogy as they measure different things, but it’s enough to see that cryptocurrencies would have a very long way to go before they form a sufficiently large energy drain to cause any significant effects on the energy industry.

Beyond the energy industry, another great benchmark for size is the total size of the world economy. At this scale, the cryptocurrency squares are effectively invisible. But what’s that grey square on the left?

It turns out that the value of non-cash transactions made each year dwarfs even the global economy. This is the space which cryptocurrencies would wish to someday occupy- and it seems they have a fair way to go yet.

While we’re at it, let’s look at the number of users of Bitcoin in comparison to some of the other e-commerce services in the world.

From this perspective, Bitcoin isn’t quite as miniscule, but is still far smaller than any of the big established players. It’s interesting to note that the transaction volume of Bitcoin per user is actually much higher than that of established services such as Paypal; it’s possible that this is a sign of trust from users, but to my mind it’s more likely that it is just an artefact of speculative trading and the decentralised structure of a peer-to-peer market. Over the past 30 days, Bitcoin has averaged a transaction volume of around $65m per day, whilst Paypal averages $315m.

Bitcoin also fares favourably against international money transfers (IMT) in terms of transaction volume. This is another prime area in which cryptocurrencies could be used to bypass existing institutions, especially in developing economies.

So what do all these comparisons tell us? It’s clear that Bitcoin is still in its infancy compared to some of the alternative payment methods, but this also means that there is a lot more room to grow. For now, Bitcoin is unlikely to cause any price effects in the energy industry, but that isn’t to say it could never happen; if Bitcoin were to process even 1% of world non-cash transactions, the energy drain from miners would be worth taking into consideration for energy policy planners. But that would require Bitcoin to grow approximately 100-fold.

Join me for my next post, in which I look at the spread of Cryptocurrencies in Europe and North America.

Dr. Neeraj Oak continues his examination of why Bitcoin is designed the way it is. In this post, he looks at how miners are compensated for their work, and the implications this has on how Bitcoin operates. He concludes with a look at whether a transaction-fee or Bitcoin mining business model is a better bet for the future.

So who are the ‘miners’ and why do they expend computer time (and hence money) on keeping Bitcoin ticking?

Miners benefit the Bitcoin community by using CPU resources to process transactions, so the designers thought they should receive some recompense for their services. In a traditional financial-institution (FI) based payments service, the FI provides the transaction validation service in return for a transaction fee. But it is exactly these kinds of fees that the users of Bitcoin feel are unjustified, or at least far too high. So miners need to be given some other form of incentive to continue providing a validation service and to invest in expanding their service as more users adopt Bitcoin. Miners could also use a transaction fee based system, but this would be unpopular initially and might stop people from adopting the currency. So Bitcoin developed an innovative new solution- to ‘discover’ more Bitcoins.

The term mining is meant to draw a parallel between the process of validating transactions and the creation of wealth through costly labour. When a block is successfully processed, the person who found the solution receives a reward in Bitcoins. This both provides a cash incentive for the miner, but also ties them ever closer to the Bitcoin community, as the continuing success of Bitcoin is the only guarantee of the value of the reward. As such, no miner can ever afford for Bitcoin to collapse, as the value of their earnings from mining would collapse with it. This forces them to either immediately cash their earnings into some other currency or reinvest a portion in expanding their computing capacity to continue to mine successfully in future.

There’s a problem with mining though- inflation. Let’s take an example from history. When the Spanish discovered the huge gold and silver deposits of South America in the 16th century, they were quick to extract as much as possible, mint it into coins and ship in home to Spain. But once that money arrived and started being spent, the Spanish suddenly found that everything started to go up in price. Why did that happen? Well, the total amount of goods and services in Spain hadn’t gone up much, whereas there was suddenly a whole lot of extra money in the economy. What happens in this situation is that people simply outbid each other for the goods they need or want, and this slowly but surely pushes prices up. The result was that went from one of the richest and largest empires in history to an economic basket-case by the 18th century, as the influx of American gold ate away at the domestic Spanish economy.

So inflation can be a bad thing. How did the designers of Bitcoin get around this problem?

The first step was to establish a rule that makes the difficulty of solving blocks become progressively harder after a certain number of blocks are solved. The second step was to limit the total number of new bitcoins that can ever be mined.

Raising difficulty forces up the cost of mining bitcoins, as problems take more computer time to solve. This reduces the number of people willing to mine purely for the Bitcoin reward as time goes on, as the profit margins from doing so reduces.

Limiting the total number of Bitcoins ensures that there is a hard cap on inflation, and that the currency retains user confidence in the long run as nobody can simply ‘print more money’, as is the case with fiat currencies.

There is a problem with the way these rules interact- as mining grows more difficult, and the number of remaining minable Bitcoins grows smaller, the currency might actually become a deflationary one. Add to this the effect of lost or frozen Bitcoins and the deflationary pressure could be quite substantial. The risks posed by deflation are high, but I will cover this in more detail in a later blog.

Returning to miners, has the incentive structure offered by Bitcoin’s designers been effective? At the moment, about 13 million out of a maximum of 21 million Bitcoins have been mined. I mentioned earlier that miners are incentivised to keep mining because it helps the Bitcoins they earn to hold their value; unfortunately, while this effect may well be true, it is completely masked by the effects of speculation.

The green shaded area in the graph above shows the total number of Bitcoins in the world over time, and the blue line shows their price. If the main incentive for miners was to stabilise the price of Bitcoin, then there should be at least some correlation between the two datasets. But there doesn’t seem to be any. My view is that this is almost entirely down to the effect of speculators. And so far, it seems to be working in the miners’ favour.

Let’s look at the true worth of all those Bitcoins: their market capitalisation.

The market capitalisation of Bitcoin, shown as the orange shaded area above, is calculated by multiplying the number of available bitcoins by the price of bitcoins at any given moment.

For a commodity that is completely free of speculation and does not get destroyed by usage but is produced at a steady rate, the price of the commodity should slowly decline. At the same time, more of the commodity is always available, and each new unit should grant at least some profit for the producer, otherwise it would not be worth creating. As such, the market capitalisation should slowly increase until it is no longer worth creating more of the commodity, or it is not possible to create any more. This is a rather sober and rational market in which to operate, and it is my belief that this is the business model that the creators of Bitcoin would have envisaged for miners.

Instead, miners face a far less stable business model in which the value of the coins they create rises and plunges wildly. In a sense, they must become speculators themselves in order to get the most value from their mined Bitcoins. Yet by participating in the speculation, they make it even worse, perpetuating what might become a destructive cycle.

My final point on the way Bitcoin mining is designed is to emphasise that mining should be thought of as a stopgap, not an integral part of Bitcoin. It is a mechanism by which the first adopters of the cryptocurrency could operate effectively and earn enough money to keep investing in the growth of the Bitcoin concept. Transaction fees are the real long-term mechanism for revenues, and this is where mainstream organisations should look to invest, not in mining.

I’ll leave you with an analogy that illustrates this point. Bitcoin mining is, in many ways, like the California gold rush of the late 1840s. It’s a chance for people to get rich quick, but it’s also tough, risky and best suited to people with nothing to lose. Big companies did not invest in the gold rush of the 1840s, but they did put their money into developing California by building railroads and cities. In total, the California gold rush dug up around $20-30 billion in today’s money. Compare this to the GDP of California- around $1.8 trillion. That’s around a thousand times more than the value of the gold rush each year. Perhaps investors in Bitcoin should start to look at the more boring but predictable transaction model rather than the lottery that is Bitcoin mining. Because if the gold rush analogy holds, that’s where the real money is.

Dr. Neeraj Oak continues his examination of why Bitcoin is designed the way it is. In this post, he looks at the concept of blocks and block chains, and why these security features stop fraudsters from spending the same money twice.

Let’s look at another major design feature of Bitcoin- the ‘blockchain’. Why did the designers opt to use this mechanism?

When a user makes a payment to another Bitcoin wallet, the transaction is not immediately executed. Instead, it is put together with many others into what is known as a block, ready to be processed. Processing a block involves verifying that all the transactions within it are valid and consistent, and that no Bitcoins have been spent twice.

Double-spending is a potentially fatal problem for a cryptocurrency; what stops someone from spending the same money twice? Ordinarily, the first person to be promised money should be entitled to it, but if nobody is tracking the history of promises, it is possible to promise the same money to two people, and then indefinitely defer payments by pointing to conflicting transactions in the ledger.

Once a block has been successfully processed or mined, the person who mined it announces the solution of the block. ‘Solving’ a block involves deciphering a mathematical problem that is partly a function of all the transactions in the block, but also contains a random element. This means that the miner must perform a lot of computational work to properly process it. But the beauty of the system is that, once processed, it is easy for someone else to verify that a solution is correct. A good analogy would be trying to open a combination lock. You might successfully guess the combination on your first try, or it might take you all day. But once you know the combination, you can tell someone else, and all they would have to do to check if your combination is correct is to try it on the lock and see if it opens. As such, finding a solution is far harder than checking it.

If a block is solved, it is placed after a previous block in chronological order; this is called a chain. In the rare situation that two people solve the same block simultaneously (but with different solutions- remember that the problem is partly random), both blocks are initially considered to be valid but parallel solutions. The tie is broken when someone solves the next block, which is necessarily built upon the solution of one of the previous blocks. It is even more unlikely that two people will solve this next block simultaneously for each of the parallel block chains, but if this happens, both continue in parallel until a block is solved for one but not the other. At this point, the longer chain always wins, and the parallel track is discarded. The discarded blocks are said to be orphaned.

The block chain method is a fairly efficient way of solving the double spend problem and spotting fraudulent transactions, but it also has one more feature that helps it frustrate potential attackers.

If someone was very keen on putting through a fraudulent transaction, what stops them from falsifying an entire block in order to cover their tracks? Firstly, it’s a great deal of work, but the system also rather cleverly pits such attackers against the entire mining community in a race they are bound to lose. To see how this works, let’s imagine the attacker wants to falsify a transaction that happened a few blocks ago. The attacker would have to not only falsify the block that transaction’s block, but every subsequent block, as his version of history will only be accepted if it is the longest block chain. The problem is, other miners are solving blocks at the same time, so the attacker would need to solve blocks faster than every other miner put together in order to eventually overtake the size of the largest block chain. This is the equivalent of a 51% attack, and as we’ve seen earlier, this is usually more expensive to perform than the rewards it yields.

Join me for my next post, in which I consider why the designers of Bitcoin chose to reward the people who verify transactions with ‘mined’ Bitcoins.

Dr. Neeraj Oak continues his examination of why Bitcoin is designed the way it is. In this post, he concentrates on the concept of a shared transaction ledger, and examines the concept of a ‘51% attack’.

A feature of decentralised systems such as cryptocurrencies is that there is no one entity dedicated to keeping the ‘history’ of the system in order. If one entity did control the history of the system, it would be possible for that entity to, either by incompetence or malfeasance, adjust past transactions. This could be used to steal funds, or make them disappear or appear at will.

The only solution is for everybody to keep the history of the system simultaneously. This sounds like a difficult proposition, but it’s actually quite simple. Every user of Bitcoin maintains a copy of the same ‘ledger’ of transactions on their device, and this ledger can only be updated by public announcements.

To see how this works, imagine someone making fraudulent changes to the ledger on their machine. The next time their ledger is compared to that of another user, the mismatch will become apparent. All the other user needs to do to verify that the person they are dealing with is a fraudster is to compare ledgers with a large number of other users, and to accept the most commonly held ledger as genuine. This means that a criminal would need to include over 50% of the machines on the network to make adjustments to the ledger and get away with it. This is known as a “51% attack”. However, this kind of attack is unlikely to occur for well-established cryptocurrencies such as Bitcoin because the cost of buying up or suborning so many machines into a single criminal conspiracy would be enormous. Indeed, such an attack hardly seems worthwhile, as it’s unlikely to obtain more money than it costs to perform. This may not be the case for smaller cryptocurrencies which have low market capitalisation. However, once it becomes known that a currency has been compromised, it becomes worthless very quickly, so 51% attacks on these currencies don’t seem worthwhile either.

An interesting side effect of this design is that every user of the system has a complete record of all the transactions ever made through the system. This actually has some radical privacy implications that aren’t always made clear. It would be rather like your bank erasing all the names from your monthly bank statements and then handing copies to any criminals, government agencies, friends and neighbours who ask for it. While it doesn’t mean that any of these people can directly exploit the information or steal your money, it would certainly make me uncomfortable.

Join me for my next blog post, in which I look at blocks, chains and the double-spending problem.